Background

Electric vehicles powered with large-scale battery packs are gaining popularity as gasoline price soars. Large-scale battery packs usually consist of an estimated 12,000 battery cells connected in series and parallel, which are susceptible to battery cell failures. Currently available battery-management systems are often dedicated to micro-scale batteries based on static configuration, and hence limited to physical processes. As a result, more interactive computations online are required to cope with a large-scale battery-management system are required.

Technology

Researchers at the University of Michigan have developed a dynamic reconfiguration framework that monitors, reconfigures, and controls large-scale battery packs online. The framework is built upon a syntactic bypassing mechanism that provides a set of rules for changing the battery-pack configuration, and a semantic bypassing mechanism by which the battery-cell connectivity is reconfigured to recover from a battery-cell failure. In particular, the semantic bypassing mechanism is dictated by constant-voltage-keeping and dynamic voltage- allowing policies. The former policy is effective in preventing unavoidable voltage drops during the battery discharge, while the latter policy is effective in supplying different amounts of power to meet a wide-range of application requirements.

Applications and Advantages

Applications

Monitoring, reconfiguration, and control of large set battery packs online

Advantages

Lengthened battery pack operation time due to high resilience to battery cell failures

Increased level of fault-tolerance as compared to a legacy scheme

Enhanced applicability and deployability owing to customizability of reconfiguration framework